REDEFINITION OF THE JIAONAN ROCK GROUP IN SHANDONG AND THE ESTABLISHMENT OF THE PENGHESHI FORMATION

The original Jiaonan Group in the Jiaonan area is dismembered into three stratigraphic se-quences :（1）the Late Archean Dashangou Rock Formation in the lower part , represented by bi-otite granulitite and leucogranulitite with amphibolite;（2） the Early Proterozoic Jiaonan RockGroup in the middle part,including the Qiuguanzhuang Rock Formation dominated by granulititein the lower and the Yujialing Rock Formation marked by schist and granulitite with arkosite andmarble in the upper;（3）the Sinian Pengheshi Formation in the upper part ,represented by a low-grade metamorphic rock association consisting of meta-arkosite and meta-arkose with quartzite,metaconglomerate and phyllite.